Hospitals, nursing homes, and other patient care facilities typically include patient monitoring devices at one or more bedsides in the facility. Patient monitoring devices generally include sensors, processing equipment, and displays for obtaining and analyzing a medical patient's physiological parameters such as blood oxygen saturation level, respiratory rate, pulse, and a myriad of other parameters, such as those monitored on commercially available patient monitors from Masimo Corporation of Irvine, Calif. Clinicians, including doctors, nurses, and other medical personnel, use the physiological parameters and trends of those parameters obtained from patient monitors to diagnose illnesses and to prescribe treatments. Clinicians also use the physiological parameters to monitor patients during various clinical situations to determine whether to increase the level of medical care given to patients.
In an embodiment, the patient monitoring devices include a pulse oximeter. Pulse oximetry is a widely accepted noninvasive procedure for measuring the oxygen saturation level of arterial blood, an indicator of a person's oxygen supply. A typical pulse oximetry system utilizes an optical sensor clipped onto a fingertip to measure a relative volume of oxygenated hemoglobin in pulsatile arterial blood flowing within, for example, the fingertip, foot, ear, forehead, or other measurement sites. The oximeter can, in various embodiments, calculate oxygen saturation (SpO2), pulse rate, a plethysmograph waveform, perfusion index (PI), pleth variability index (PVI), methemoglobin (MetHb), carboxyhemoglobin (CoHb), total hemoglobin (tHb), glucose, and/or otherwise, and the oximeter can display on one or more monitors the foregoing parameters individually, in groups, in trends, as combinations, or as an overall wellness or other index. An example of such an oximeter, which can utilize an optical sensor described herein, are described in U.S. application Ser. No. 13/762,270, filed Feb. 7, 2013, titled “Wireless Patient Monitoring Device,” U.S. application Ser. No. 14/834,169, filed Aug. 24, 2015, titled “Wireless Patient Monitoring Device,” and U.S. application Ser. No. 14/511,974, filed Oct. 10, 2014, titled “Patient Position Detection System,” the disclosures of which are hereby incorporated by reference in their entirety.
The patient monitoring devices can also communicate with an acoustic sensor comprising an acoustic transducer, such as a piezoelectric element. The acoustic sensor can detect respiratory and other biological sounds of a patient and provide signals reflecting these sounds to a patient monitor. An example of such an acoustic sensor, which can implement any of the acoustic sensing functions described herein, is described in U.S. application Ser. No. 12/643,939, filed Dec. 21, 2009, titled “Acoustic Sensor Assembly,” and in U.S. application Ser. No. 61/313,645, filed Mar. 12, 2010, titled “Acoustic Respiratory Monitoring Sensor Having Multiple Sensing Elements,” the disclosures of which are hereby incorporated by reference in their entirety. An example of such an acoustic sensor is also described in U.S. application Ser. Nos. 13/762,270, 14/834,169, and 14/511,974 referenced above.